A Moscow appeals court upheld the conviction of ex-Yukos oil director Mikhail Khodorkovsky, although it also reduced his prison sentence by one year. The decision is the culmination of a long legal process critics say is politically motivated.

The appeals court judges upheld the conviction of Mikhail Khodorkovsky and his key business partner of fraud and tax evasion last May.

The judges then reduced the nine-year prison sentences for the two men by one year.

The ruling came after less than an hour of deliberations, and after a long day in which lawyers for the jailed oil director sparred repeatedly with the chief prosecutor in the case.

One of his attorneys, Yuri Schmidt, said the legal proceedings were reminiscent of Soviet times, and that the sentence reduction was a way to show the court was impartial.

Mr. Schmidt also says there was no time in which to go through thousands of pages of documents in order to present the defense's arguments.

The Kremlin has long insisted the case is strictly a legal matter. But critics have charged that the long-running "Yukos affair" was a way for the Kremlin to silence a political opponent.

Before his arrest two years ago Mr. Khodorkovsky had funded opposition political parties and become more critical of President Vladimir Putin.

Most recently, the businessman, 42, announced plans to run for a seat in parliament in a December by-election.

Mr. Khodorkovsky was able to do this as long as his appeal was pending, and last week his lawyers said the appeals process was sped up in order to make him ineligible.

Mr. Khodorkovsky was once Russia's richest man with an estimated net worth of around 15 billion dollars, much of this in Yukos stock when the company was Russia's largest oil firm.

However the company has effectively been dismantled, its primary oil pumping subsidiary auctioned off to a state-connected oil firm.